24
heating performance and could experience excessive or pre-
mature component failures.
Prevent sheetrock dust or other debris from settling on coil
fins, motor-blower assembly or other unit interior surfaces.
EXPOSED UNIT FINISH, TOUCH-UP AND REPAINT
Return access and exposed cabinet units may be furnished
with a baked enamel finish. Small scratches in this finish may
be repaired with touch-up paint available from the factory.
Some colors of touch-up paint are available in aerosol con-
tainers and all touch-up paint is available in pint, quart, and
gallon cans.
To repaint the factory-baked enamel, the finish should be pre-
pared by light sanding with no. 280 grit sand paper or no. 000
or no. 0000 fine steel wool. The surface may also be wiped
with a liquid surface etch cleaning product such as “No Sand”
or “Pasceo.” These items should be available at most paint
product stores. It should be noted that the more conscien-
tiously this preparation is done, the more effective it will be.
After this preparation is accomplished, the factory finish
should provide excellent adhesion for a variety of air-dried
top coats. Enamel will give a more durable, higher gloss fin-
ish, while latex will not adhere as well and will give a dull,
softer finish. Top coats involving an exothermic chemical
process between two components, such as epoxies and ure-
thanes, should be avoided.
Factory aerosol touch-up paint may require a number of light
“dust coats” to isolate the factory-baked enamel finish from
the quick drying touch-up paint.
Step 5 — Cut Out Openings for Grilles and
Thermostats
On all units with optional supply-air or return-air grilles,
dampers, thermostats, and switch plates, cut out openings
where specified on the job plans. Be careful not to cut wires,
piping or structural supports.
For remote-mounted thermostats, use a steel thermostat shield
ring to protect drywall from thermostat wiring where applicable.
If not included on the unit or furnished from the factory, sup-
ply and return grilles should be provided as recommended in
the product catalog.
Step 6 — Make Final Preparations
1. Turn off power to the unit (open unit electrical disconnect).
2. Install thermostats and perform any other final wiring as
applicable. Check the unit for any loose wires.
3. Perform a final visual inspection. All equipment, ple-
nums, ductwork, and piping should be inspected to verify
that all systems are complete and properly installed and
mounted, and that no debris or foreign articles such as
paper or drink cans are left in the units or other areas.
Clean dirt, dust, and other construction debris from unit
interior. Be sure to check fan wheel and housing.
4. Rotate fan wheel by hand to be sure it is free and does
not rub housing. Check that wing nuts securing fan
assembly to fan deck are tight.
5. Ensure all panels and filters are installed before checking
fan operation. Turn on power to the unit.
6. Install filter in frame at front of coil. If field-supplied fil-
ters are used, be sure size is as specified in Table 1.
7. ECM (Electronically Commutated Motor) Blower:
If the unit is equipped with an ECM blower, additional
steps may be required during the air balancing process.
The ECM blower is controlled by one of three control
boards, depending on the options ordered with the unit.
Review project submittals or order acknowledgment to
determine which ECM control scheme the unit has.
Alternatively, match the control board to the illustrations
identified in the Control Board Type section.
8. Check the fan and motor operation.
9. Be sure drain line is properly and securely positioned and
that the line is clear. Pour water into drain to check
operation.
10. Prior to the water system start-up and balancing, the
chilled/hot water systems should be flushed to clean out
dirt and debris which may have collected in the piping
during construction. During this procedure, the system
should be flushed from the supply riser to the return riser
through a cross-over loop at the end of the riser column,
and all unit service valves must be in the closed position.
This prevents foreign matter from entering the unit and
clogging the valves and metering devices. Strainers should
be installed in the piping mains to prevent this material
from entering the units during normal operation. Vent all
air from unit coil and related piping. Air venting from the
unit is accomplished by the use of the standard manual air
vent fitting, or the optional automatic air vent fitting
installed on the coil. Venting can be accomplished by
depressing the needle valve core. Automatic air vents may
be unscrewed one turn counterclockwise to speed initial
venting, but should be screwed in for automatic venting
after start-up operations. When steady steam of water
begins to escape, close valve. Vent release air slowly, usu-
ally dripping water into drain pan in the process.
Make sure all service valves are open and that the motor-
ized control valves, if supplied, are set for automatic
operation.
11. Check all control valves in the system for proper opera-
tion in accordance with valve manufacturer's instruc-
tions.
12. For units with factory-installed ball valves with lever
handles:
When handle is perpendicular to valve body, there is no
flow through valve. Ball valves may be used as shutoff
valves.
CAUTION
Proper safety procedures should be followed regarding
ventilation and safety equipment during touch-up and re-
painting since materials may pose a health hazard. The
manufacturer's directions should be followed for the prod-
ucts being used.
CAUTION
Do not start up or operate unit without filter. Be sure filter
and unit interior are clean. Failure to do so could result in
damage to the equipment or building.
CAUTION
The air vent provided on the unit is not intended to replace
the main system air vents and may not release air trapped
in other parts of the system. Inspect the entire system for
potential air traps and vent those areas as required, inde-
pendently. In addition, some systems may require repeat-
ed venting over a period of time to properly eliminate air
from the system. Failure to properly vent system may
negatively affect operation.
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